In oriental culture, it has been widely believed for a long time that tea has medicinal efficacy in preventing and treatment of many diseases. Scientific and medical evaluation of tea, however, started only very recently. Early epidemiological studies yielded inconclusive evidence whether tea is medically beneficial. It is found that green tea contains polyhydroxylated benzene-containing compounds. Thus, it should be explored whether these compounds or derivatives thereof are beneficial to health.
An aspect of this invention relates to a method for reducing food intake in a subject. The method comprises administering to the subject in need thereof an effective amount of a compound of formula (I): 
A is a C1-14 hydrocarbon, an oxygen, a sulfur, or a nitrogen. The hydrocarbon is selected from a group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, aryl, and heteroaryl. Each of the just-mentioned moieties is optionally substituted with alkoxy, hydroxyl, hydroxylalkyl, carboxyl, halo, haloalkyl, amino, thio, nitro, cyano, oxo, alkylcarbonyloxy, alkyloxycarbonyl, arylcarbonyloxy, aryloxycarbonyl, alkylcarbonyl, arylcarbonyl, formyl, aminocarbonyl, alkylcarbonylamino, arylaminocarbonyl, or arylcarbonylamino. Each of Ra, Rb, Rc and Rd, independently, is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, aryl, heteroaryl, aralkyl, heteroaralkyl, alkoxy, hydroxyl, hydroxylalkyl, carboxyl, halo, haloalkyl, amino, aminoalkyl, thio, thioalkyl, nitro, cyano, alkylcarbonyloxy, alkyloxycarbonyl, alkylcarbonyl, formyl, aminocarbonyl, alkylcarbonylamino, or a moiety of formula (II): 
L is xe2x80x94L1xe2x80x94L2xe2x80x94L3xe2x80x94. L2 is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94N(Rxe2x80x2)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94N(Rxe2x80x2)xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94N(Rxe2x80x2)xe2x80x94, xe2x80x94N(Rxe2x80x2)xe2x80x94SO2xe2x80x94, xe2x80x94SO2xe2x80x94N(Rxe2x80x2)xe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94SO2xe2x80x94, xe2x80x94SO2xe2x80x94Oxe2x80x94, or deleted. Each of L1 and L3, independently, is xe2x80x94(CRxe2x80x2xe2x95x90CRxe2x80x3)nxe2x80x94, xe2x80x94(Cxe2x89xa1C)nxe2x80x94, xe2x80x94(C(Rxe2x80x2)(Rxe2x80x3))nxe2x80x94; or deleted. Each of Rxe2x80x2 and Rxe2x80x3, independently, is hydrogen, alkyl, alkoxy, hydroxylalkyl, hydroxyl, amino, nitro, cyano, halo, or haloalkyl, and n is 1, 2, or 3. Each of R1, R2, R3, R4, and R5, independently, is hydrogen, alkyl, alkenyl, alkynyl, alkoxy, hydroxyl, hydroxylalkyl, carboxyl, halo, haloalkyl, amino, thio, nitro, cyano, alkylcarbonyloxy, alkyloxycarbonyl, alkylcarbonyl, formyl, aminocarbonyl, alkylcarbonylamino, aminocarbonyloxy, or alkyloxycarbonylamino. Note that when A is an oxygen or a sulfur, both Ra and Rb are deleted; and when A is a nitrogen, Ra is deleted. Further, at least one (e.g., two) of Ra, Rb, Rc, and Rd is a moiety of formula (II) and at least two of R1, R2, R3, R4, and R5 are hydroxyl, alkoxy, or alkylcarbonyloxy which are at meta or ortho positions with respect to each other. A compound of formula (I) also causes a reduction in the levels of some serum nutrients, e.g., glucose, cholesterol, and triglyceride. Accordingly, a method of reducing the level of such serum nutrients using a compound of formula (I) is within the scope of this invention. Note that new compounds of formula (I) and compositions containing one or more of the new compounds, are also within the scope of this invention.
Another aspect of this invention relates to a method for reducing the levels of an endocrine in a subject. The method comprises administering to the subject in need thereof an effective amount of a compound of formula (I), supra. An endocrine is a chemical substance produced in an endocrine system, e.g., a hormone. The endocrines whose levels are affected by a compound of formula (I) include testosterone, estradiol, leptin, insulin, insulin-like growth factor, and luteinizing hormone. A method of inhibiting growth of organs such as prostate, seminal vesicles, coagulating gland, uterus, and ovary by administering a compound of formula (I) is also within the scope of the present invention.
A further aspect of this invention relates to a method of treating a disorder or a disease related to elevated levels of the above-mentioned endocrines or nutrients. The method involves administering to a subject in need thereof an effective amount of a compound of formula (I) decribed above. Some examples of such a disorder or disease are benign prostatic hyperplasia, prostate cancer, skin disorder (e.g., acne), seborrhea, common baldness, hirsutism, hidradenitis suppurative, obesity, breast cancer, ovarian cancer, type II diabetes, cardiovascular diseases, angiogenesis, diabetic retinopathy, rheumatoid arthritis, inflammation, hemagiomas, and psoriasis. The use of a compound of formula (I) for the manufacture of a medicament for treating the above-mentioned disorders or diseases is also within the scope of this invention.
A still further aspect of this invention relates to a liposomal preparation containing a liposome and a compound of formula (I), supra, entrapped therein. The liposome can be formed of lipids such as phosphatidylcholine, phosphatidylethanolamine, phosphotidylserine, cardiolipin, phosphotidylinositol, and cholesterol sulfate.
Set forth below are some examples of compounds of formula (I): 
A pharmaceutically acceptable salt of a compound of formula (I) can be formed, for example, between a compound of formula (I) having a carboxylate and a cationic counterion such as an alkali metal cation, e.g., a sodium ion or a potassium ion; or an ammonium cation that can be substituted with organic groups, e.g., a tetramethylammonium ion or a diisopropyl-ethylammonium ion. A salt of a compound of formula (I) can also be formed between a compound of formula (I) having a protonated amino group and an anionic counterion, e.g., a sulfate ion, a nitrate ion, a phosphate ion, or an acetate ion.
It should be recognized that a compound of formula (I) may contain chiral carbon atoms. In other words, it may have optical isomers or diastereoisomers. These isomers are all within the scope of this invention.
As used herein, alkyl is a straight or branched hydrocarbon chain containing 1 to 14 carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylhexyl, 3-ethyloctyl, and 4-ethyldecyl.
The terms xe2x80x9calkenylxe2x80x9d and xe2x80x9calkynylxe2x80x9d refer to a straight or branched hydrocarbon chain containing 2 to 14 carbon atoms and one or more (e.g., 1-7) double or triple bonds, respectively. Some examples of alkenyl and alkynyl are allyl, 2-butenyl, 2-pentenyl, 2-hexenyl, 2-butynyl, 2-pentynyl and 2-hexynyl.
By cycloalkyl is meant a cyclic alkyl group containing 3 to 14 carbon atoms. Some examples of cycloalkyl are cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, and norbornyl. Heterocycloalkyl is a cycloalkyl group containing 1-6 heteroatoms such as nitrogen, oxygen, or sulfur. Examples of heterocycloalkyl include piperidinyl, piperazinyl, tetrahydropyranyl, tetrahydrofuryl, and morpholinyl. Cycloalkenyl is a cycloalkyl group containing one or more (e.g., 1-3) double bonds. Examples of such a group include cyclopentenyl, 1,4-cyclohexa-di-enyl, cycloheptenyl, and cyclooctenyl groups. By the same token, heterocycloalkenyl is a heterocycloalkyl group containing one or more double bonds.
As used herein, aryl is an aromatic group containing 6-14 ring atoms and can contain fused rings, which may be saturated, unsaturated, or aromatic. Examples of an aryl group include phenyl, naphthyl, biphenyl, phenanthryl, and anthracyl. Heteroaryl is aryl containing 1-3 heteroatoms such as nitrogen, oxygen, or sulfur and can contain fused rings. Some examples of heteroaryl are pyridyl, furanyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, indolyl, benzofuranyl, and benzthiazolyl.
Note that an amino group can be unsubstitued, mono-substituted, or di-substituted. It can be substituted with groups such as alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, faralkyl, or heteroaralkyl. Halo refers to fluoro, chloro, bromo, or iodo. Some examples of a monosaccharide are pentose and hexose.
Other features or advantages of the present invention will be apparent from the following detailed description, and also from the claims.
The invention relates to the use of a polyhydroxylated benzene-containing compound of formula (I), supra, for reducing food intake; lowering the levels of certain endocrines (e.g., testosterone, estradiol, leptin, insulin, insulin-like growth factor-I (IGF-I), and luteinizing hormone (LH)) and nutrients (e.g., glucose, cholesterol, and triglyceride) in the blood; treating or preventing any disorder or disease that is mediated by elevated levels of these endocrines or nutrients; and decreasing the growth of certain organs (e.g., prostate, uterus, and ovary) in a subject. EGCG or its derivatives can be administrated in various methods including intraperitoneal injection or oral administration in the form of a liposomal preparation.
Compounds of formula (I) can be obtained from natural sources. For example, (xe2x88x92)epigallocatechin-3-gallate (EGCG) and (xe2x88x92)epicatechin-3-gallate (ECG) can be isolated from green tea (Camellia sinensis) according to the procedure described in Liao et al., Biochem. Biophys. Res. Commum 214: 833-838 (1995). Some compounds of formula (I), e.g., tannin, are also commercially available from known chemical vendors such as Sigma Chemical Co. (St. Louis, Mo.). Alternatively, Compounds of formula (I) can be prepared synthetically as described below.
Compounds of formula (I), as described above, contains a multiple hydroxylated benzene moiety which is linked to moiety A via a linker L. See formula (II) supra. Compounds of formula (I) wherein L contains an amide bond can be formed by reacting an amine-containing Axe2x80x2 with a carboxyl-containing Raxe2x80x2. Note that Axe2x80x2 and Raxe2x80x2 are compounds which, upon reacting with each other, yield moieties of A and Ra, respectively. Referring to the first reaction shown scheme I below, compound Axe2x80x2 is gallic acid and compound Raxe2x80x2 is 6-hydroxydopamine. These two compounds are coupled in the presence of a common coupling reagent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), benzotriazol-1-yloxytris(dimethylamino)-phosphonium hexafluorophosphate (BOP), or O-benzo-triazol-1-yl-N,N,Nxe2x80x2,Nxe2x80x2-tetramethyluronium hexafluorophosphate (HBTU) to form compound X. Similarly, caffeic acid and 3-O-methydopamine can be coupled to form compound XII. See the last reaction of Scheme I. Compound XI, wherein L contains a carbonyl, can be prepared by reacting methyl 3,4,5-trimethoxybenzoate with 4-dimethylaminiobenzaldehyde in an alkaline medium. See the second reaction of Scheme I. 
Schemes II-V below describe methods of preparing compounds of formula (I) in which A is an alkenyl or an aryl. 
Compounds of formula (I) prepared by synthetic methods discussed above can be purified by flash column chromatography, preparative high performance liquid chromatography, or crystallization.
As mentioned above, a compound of formula (I), reduces food intake and inhibits growth of organs such as prostate, seminal vesicles, coagulating gland, uterus, and ovary. It also reduces the circulating levels of certain endocrines and nutrients in the subject. Such endocrines and nutrients include testosterone, estradiol, leptin, insulin, insulin-like growth factor-I, luteinizing hormone, glucose, cholesterol, and triglyceride. Diseases or conditions relating to elevated levels of the just-mentioned endocrines and nutrients include benign prostatic hyperplasia, prostate cancer, skin disorder (e.g., acne), seborrhea, common baldness, hirsutism, hidradenitis suppurative, obesity, breast cancer, ovarian cancer, type II diabetes, cardiovascular diseases, angiogenesis, diabetic retinopathy, rheumatoid arthritis, inflammation, hemagiomas, and psoriasis. All of the just-mentioned conditions or diseases are treatable by administering an effective amount of a compound of formula (I) or its salt to a subject in need thereof.
An effective amount is defined as the amount of a compound of formula (I) which, upon administration to a subject in need, confers a therapeutic effect on the treated subject. The effective amount to be administered to a subject is typically based on body surface area, subject weight, and subject condition. The interrelationship of dosages for subjects (based on milligrams per meter squared of body surface) is described by Freireich et al., Cancer Chemother. Rep. 1966, 50, 219. Body surface area may be approximately determined from height and weight of the subject. See, e.g., Scientific Tables, Geigy Pharmaceuticals, Ardley, N.Y., 1970, 537. An effective amount of a compound of formula (I) used to practice the invention can range from about 1 mg/kg to about 2 g/kg, e.g., from about 1 mg/kg to about 1 g/kg, from about 1 mg/kg to about 500 mg/kg, or from about 1 mg/kg to about 150 mg/kg. Effective doses will also vary, as recognized by those skilled in the art, dependant on route of administration, excipient usage, and the possibility of co-usage with other therapeutic treatments.
A pharmaceutical composition containing a compound of formula (I) may be administered via the parenteral route, including subcutaneously, intraperitoneally, intramuscularly and intravenously. Examples of parenteral dosage forms include aqueous solutions of the active agent, in a isotonic saline, 5% glucose or other well-known pharmaceutically acceptable excipient. Solubilizing agents such as cyclodextrins, or other solubilizing agents well-known to those familiar with the art, can be utilized as pharmaceutical excipients for delivery of the therapeutic compounds.
Compounds of formula (I) can also be formulated into dosage forms for other routes of administration utilizing well-known methods. They can be formulated, for example, in dosage forms for oral administration in a gel seal, a syrup, a capsule, or a tablet. Capsules may comprise any well-known pharmaceutically acceptable material such as gelatin or cellulose derivatives. Tablets may be formulated in accordance with the conventional procedure by compressing mixtures of the compound of this invention and a solid carrier, and a lubricant. Examples of solid carriers include starch and sugar bentonite. The steroid derivatives of this invention can also be administered in a form of a hard shell tablet or a capsule containing a binder (e.g., lactose or mannitol) and a conventional filler.
Compounds of formula (I) can be administered via any appropriate route, e.g. intravenously, intraarterialiy, topically, by injection, intraperitoneally, intrapleurally, orally, subcutaneously, intramuscularly, sublingually, intraepidermally, or rectally. It can be formulated as a solution, suspension, suppository, tablet, granules, powder, capsules, ointment, or cream. In the preparation of these compositions, a solvent (e.g., water or physiological saline), solubilizing agent (e.g., ethanol, Polysorbates, or Cremophor EL7), agent for making isotonicity, preservative, antioxidizing agent, excipient (e.g., lactose, starch, crystalline cellulose, mannitol, maltose, calcium hydrogen phosphate, light silicic acid anhydride, or calcium carbonate), binder (e.g., starch, polyvinylpyrrolidone, hydroxypropyl cellulose, ethyl cellulose, carboxy methyl cellulose, or gum arabic), lubricant (e.g., magnesium stearate, talc, or hardened oils), or stabilizer (e.g., lactose, mannitol, maltose, polysorbates, macrogols, or polyoxyethylene hardened castor oils) can be added. If necessary, glycerin, dimethylacetamide, 70% sodium lactate, a surfactant, or a basic substance such as sodium hydroxide, ethylenediamine, ethanolamine, sodium bicarbonate, arginine, meglumine, or trisaminomethane can be added. Pharmaceutical preparations such as solutions, tablets, granules or capsules can be formed with these components.
A method for orally administering a compound of formula (I) is by administering a liposomal preparation containing a liposome and a compound of formula (I) entrapped therein. Liposomes are lipid bilayer vesicles that form spontaneously, in the presence of water. Liposomes can be made from a variety of amphiphilic lipids. Phosphatidyl-choline is the most common phospholipid used to make liposomes, but other amphiphilic lipids, such as phosphatidylethanolamine, phosphotidylserine, cardilipin, phosphotidylinositol, and cholesterol sulfate can also be used. Liposomes can be made using a single type of lipid or can be composed of a mixture of components. For example cholesterol (or other sterols) is often added to liposomes composed of phosphatidylcholine to stabilize them in biological fluids. Depending on the preparative method employed, multilammelar and/or unilamellar vesicles are formed. These vesicles can be either large (0.1-100 xcexcm) or small (0.025-0.1 xcexcm) in diameter. Multilamellar liposomes, which are the type being used in this project, are made by dissolving lipids and nonpolar drugs in organic solvent and then the mixture is dried on the walls of a glass vesicle under reduced pressure. An aqueous buffer containing a compound of formula (I), e.g., EGCG, is then added and the mixture shaken vigorously to disperse the lipids. This step must be performed above the gel-liquid-crystalline phase transition temperature for a gene lipid composition. This temperature depends on the individual components of the liposomes and on, the fatty acid composition of the phospholipids in the liposome. Alternatively, liposomes loaded with a desired compound can be made by dissolving phopholipids and compound in a solvent such as acetone, and then isolating a complex of the two by precipitating them in a solvent, such as hexane or lyophilizing or spray drying the components. When this material is suspended in aqueous solvents, a liposomal complex is spontaneously formed. A dried liposomal preparation of a compound of formula (I) is stable, especially when stored under vacuum and low temperatures. Addition of antioxidants, such as ascorbic acid or butylated hydroxytoluene (BHT), may allow storage of the preparation at room temperature and ambient pressures.
Without further elaboration, it is believed that one skilled in the art can, based on the above disclosure and the description below, utilize the present invention to its fullest extent. The following examples, which describe syntheses, biological activities and formulation of a compound of formula (I), are to be construed as merely illustrative of how one skilled in the art can practice the invention and are not limitative of the remainder of the disclosure in any way. Any publications cited in this disclosure are hereby incorporated by reference.